1. Field Of The Invention
The present invention relates generally to automated handling of nuclear fuel pellets during fabrication thereof and, more particularly, is concerned with an apparatus for unloading pellets from a sintering boat in a manner which provides gentle, but efficient, transfer of the pellets from one station to another in the fabrication process.
2. Description Of The Prior Art
Conventional practice in fabrication of nuclear fuel pellets requires transfer of pellets from station to station in the manufacturing process. Heretofore, transfer between certain stations has been performed manually. For instance, pellets are sintered in a furnace while stacked in large numbers in a boat, a square-shaped molybdenum container with an open top. Following the sintering station, the pellets must be unloaded from the boat and fed individually into a grinding station. Since the pellets are hard, abrasive and subject to chipping on impact and the molybdenum boat becomes brittle with continued service, it has been common practice to manually unload the boat by inverting it manually over the feeder bowl of the grinder station. Such procedure increases the exposure of personnel to the radioactivity of the pellets and airborne particles so that elaborate protective safeguards must be taken. Also, with several thousand pellets being contained in a single boat, the probability for chipping and otherwise damaging the valuable pellets is substantially increased.
Consequently, for quite some time, a need has existed for a technique to unload the nuclear fuel pellets from the sintering boat on an automated basis without the necessity for human intervention. Such technique must not only carefully handle the pellets to avoid chipping thereof, but must also gently handle the expensive, and oftentimes brittle, molybdenum sintering boat.